package com.itheima.HomeWork;

public class CalculatorDemo {
    public static void main(String[] args) {
       useCalculator((a, b) -> a + b);
    }

    public static void useCalculator(Calculator cal) {
        int a = 10, b = 20;
        System.out.println(cal.calc(a,b));
    }
}

interface Calculator {
    int calc(int a, int b);
}